By using a left-eye image equivalent to a field of view as seen from a left eye, and a right-eye image equivalent to a field of view as seen from a right eye, the left-eye image is projected to the left eye alone, and the right-eye image is projected to the right eye alone. Because of its binocular disparity, the user can obtain the stereoscopic effect from the stereoscopic image which is composed of the left-eye image and the right-eye image.
Since the stereoscopic image reproduces the disparity, which occurs between two human eyes, at least a camera for acquiring the left-eye image and a camera for acquiring the right-eye image are disposed side by side in a horizontal direction for concurrently capturing the same field of view, and thus, the stereoscopic image is created. In addition, a method exists that generates a 3D virtual space by using a computer so as to virtually achieve the same method described above, and generate a stereoscopic image from which the same effect can be obtained.
Stereoscopic images include not only still images, such as pictures, but also moving images, and are utilized for movies or the like which display a subject stereoscopically. Also, stereoscopic videos by use of a stereo video are becoming popular as a next generation method for providing audiovisual content.
As described above, stereoscopic image displaying technology has been widely used and further, it is conceived that not only a captured stereoscopic image is viewed without alternation, but some region of the captured stereoscopic image is cropped and edited.
As conventional stereoscopic image editing technology, there is a method in which a user specifies a crop-edit region of a left-eye image and a right-eye image of a stereoscopic image displayed on a display to crop and edit some region of the stereoscopic image. A user can use, for example, a same coordinate selection method or a feature point search and match method, as a method for specifying the crop-edit region.
The same coordinate selection method, if a crop-edit region is specified in one image (e.g., the left-eye image), selects a region in another image (the right-eye image) at the same coordinates of the specified crop-edit region, as a crop-edit region.
The feature point search and match method divides an image into small rectangular regions to determine an area correlation of each divided rectangular region, or the like, search the same feature points in the left-eye image and the right-eye image, and match the feature points with each other. When a crop-edit region is specified in one image (e.g., the left-eye image), a region, in another image (the right-eye image), that matches the crop-edit region specified in the left-eye image, is selected as a crop-edit region, based on the same feature point with that of the left-eye image. Patent Literature 1 discloses a stereoscopic image display apparatus which allows a user to easily view a stereoscopic image.
As described above, by specifying the crop edit regions desired by the user in the left-eye image and the right-eye image of the stereoscopic image displayed on the display, the user can crop and edit the some region of the captured stereoscopic image.